Microsoft Outlook remains one of the most popular applications for managing emails — and as a result, PST and OST files are frequent targets for data recovery efforts.

The process for Outlook data recovery will depend on the data loss scenario. Some of the most common scenarios:

• Outlook is unable to open the file or a set of folders, usually due to file corruption.
• The PST/OST file is accidentally deleted.
• Files are targeted by ransomware or other malware.
• The user’s hard drive, solid-state drive (SSD), or other data storage device fails. 

If you accidentally delete your Outlook file, your storage media fails, or you’re victimized by malware, we strongly recommend working with a professional data recovery provider. Datarecovery.com provides risk-free evaluations and a no data, no charge guarantee: If your PST/OST files aren’t recoverable, there’s no charge for the attempt.

However, if your Outlook data file is corrupt, you may be able to restore the data with the free SCANPST.EXE Inbox Repair tool. Here’s what to know before starting.

Back up your existing PST/OST file before attempting repair.

The process for backing up (or exporting) a PST/OST varies depending on your version of Outlook. Read Microsoft’s guide for backing up Outlook data.

However, professional data recovery providers will go further: Depending on the source of the data corruption, running any operation could exacerbate data loss. The safest course of action is to create a complete clone of the affected device. 

You should not attempt to back up your data within Outlook if you notice any of the signs of a physical issue with your storage device:

• You hear clicking sounds, whirring sounds, or other unusual noises.
• Your computer operates slowly or has trouble opening certain applications.
• The computer occasionally fails when booting the operating system.
• Widespread data corruption (the Outlook data file isn’t the only corrupt file on your system). 

Remember, if the data is essential, the best practice is to work with professionals. If you could recreate your Outlook data — but you’d like to avoid the extra work — you can proceed with the Inbox Repair tool.

Related: Can Data Recovery Software Fix a Corrupted Hard Drive?

The Inbox Repair tool is useful, but not perfect.

To launch the tool, you’ll need to exit Outlook and locate the SCANPST.EXE file. The location varies depending on your version of Outlook:

• Outlook 2019: C:\Program Files (x86)\Microsoft Office\root\Office16
• Outlook 2016: C:\Program Files (x86)\Microsoft Office\root\Office16
• Outlook 2013: C:\Program Files (x86)\Microsoft Office\Office15
• Outlook 2010: C:\Program Files (x86)\Microsoft Office\Office14
• Outlook 2007: C:\Program Files (x86)\Microsoft Office\Office12

After launching the tool, you’ll select the PST you want to scan. Select Start to begin the scan, then Repair to attempt to repair the damaged file.

You may need to run SCANPST.EXE several times — and the process isn’t perfect. When you restart Outlook, you may see a Lost and Found folder, which contains all of the files that the Inbox Repair tool recovered but was unable to organize. 

For more guidance, see Microsoft’s guide to using the Inbox Repair tool.

Remember, you typically have one chance to recover your data.

We’re providing information about the Inbox Repair tool for a simple reason: In some situations, it works quite well. 

However, any software data recovery tool can cause additional corruption under certain circumstances.

We recommend running SCANPST.EXE on a clone of the original hard drive/SSD; while this may seem like overkill, it significantly limits the chances of permanent data loss. If your recovery attempt fails, you’ll still have the original copy of the data — and you can work with data recovery professionals to restore your inbox.

If you’re trying to restore a PST/OST, we’re here to help. Call 1-800-237-4200 to speak with an expert or submit a case online.